1. Field of the Invention
The invention relates generally to integrated circuits and more particularly to a method and apparatus for the authentication of integrated circuits.
There is a known method of using registers to contain an internal signature of an integrated circuit, in the form of a binary word. This internal signature is used in certain cases to identify the type or the origin of the product, to enable appropriate use in terms of access time and duration of the pulse for writing data elements in the memory. In other cases, the circuit has to be authenticated in its application. Such cases relate, in particular, to chip card type products and products derived therefrom. The internal signature then consists of information of the serial number and key type, to be used by a cryptography algorithm capable of giving an authentication certificate. If the card is not authenticated by the application system (the card reader), it is rejected. What has to be done here is to combat the falsification of cards and act against fraudulent access to confidential information contained in these cards.
2. Description of the Related Art
The authentication procedure is an integral part of the exchange protocol between the card and the application system (the reader), the securing of the authentication system being obtained by the choice of the cryptography algorithm and by the fact that the confidential data elements are not output from the card. These data elements are furthermore concealed in the card by address mixing, data encoding (permutation) or other means.
Between the simple identification and the highly secured authentication of circuits, an intermediate need has been discovered. This is the need to authenticate circuits in order to prevent the dissemination of copies of circuits. These circuits relate to current applications and not necessarily to so-called secured applications. In these applications, it is sought to identify the origin of these circuits with certainty, i.e., to authenticate them.
This need is emerging especially as a result of the large-scale miniaturization of the integrated circuits, which prevent the external marking of the packages, and also as a result of technological advances which, despite the major efforts made by integrated circuit manufacturers to find technical ways to prevent the copying of integrated circuits, can be used with varying degrees of difficulty to copy these very same circuits or at least certain circuits. All these aspects are exacerbated by the increasingly common use of integrated circuits in all fields, owing to their miniaturization, low power consumption, low cost, etc.